Thermal conductivity/ heat transfer coefficient

[lukman1]

Hi All,

Could anybody help on this one. I am currently working on a project where I need convective air thermal conductivity in pipe. It would be of great help if air convective heat transfer coefficient is know too.

I am interested in typical values. I know these values depend on several parameters, but I am interested in free convection only (ambient air condition).

Thanks

Lukky

 

[TGS4]

The information that you are looking for is so highly dependent on so many factors (especially the surface temperature of the body from which (or to which) you are transferring heat), that a simple answer is not possible.

However, I will point you to use ASTM C-680. The formulae that you need to perform these calculations are in there. Otherwise, I recommend Fundamentals of Heat and Mass Transfer by Incropera and Dewitt. (The ASTM standard references this textbook for the bulk of the formulae, so your choice either way).

 

[lukman1]

Thanks TGS4. I will try your suggestions. My material is steel pipe with surface temperature an average mean anual ground temperature. For the area of the project it is around 5°C.

Thanks